Investigating the dewaterability and resource recovery potential of distillery wastewater using sawdust and charcoal dust as conditioners

Abstract

Discharge of untreated distillery wastewater has a high impact on human and environmental health. One of the critical stages in its management is dewatering. However, understanding the dewatering characteristics of distillery wastewater is a grey area as minimal research has been done on it. This research evaluated the characteristics of distillery wastewater from various sources to identify any variations, its dewatering potential, enhancement of dewatering using conditioners and its resource recovery potential. The research was undertaken using laboratory measurements and experiments to determine the wastewater characteristics and dewaterability. Dewatering performance was measured in terms of capillary suction time (CST), and turbidity of supernatant after natural and mechanical settling. The findings of this study showed that distillery wastewater characteristics were very significant in pH (3.56-6.32) p=0.017, EC (4.22-34.77mS/cm) p=0.002, COD (63,800-148,680mg/L) p=0.004 and turbidity (18,700-45,500NTU) – p=0.167. Dewatering was noted to be CST (30-5512.64s) p=0.140 and turbidity of supernatant (14,700-87,500NTU) p=0.046. Enhancing dewatering using conditioners showed CST (60.56-9047.04s) p=0.452, 0.012, 0.207 and turbidity of supernatant (4.37-93,500NTU) p=0.002, 0.013, 0.788 with better performance observed after treatment with charcoal dust. Based on the Nitrogen (31-121mg/L), Phosphorus (195-757mg/L), Potassium (4580-13449.15mg/L) and TVS/TS ratio (0.76-0.91) values, distillery wastewater showed potential for resource recovery. Distillery wastewater needs to be treated to protect human and environmental health. Strict measures should be put in place to ensure adherence to standards for discharge into the environment.